This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The aim of this project is to use X-Ray fiber diffraction techniques to characterize and map the fibrous connective tissue structure of the back of the eye including the junction with the optic nerve. Comparison of the fiber ultrastructures of healthy (non-progressive myopia and non-glaucoma) versus age-matched tissue with known progressive myopia, glaucoma and optic neuropathy will be examined. The specific aim is to quantify the collagen intermolecular and interfibrillar spacings. The preferred fiber orientation, abundance and organization will be characterized and compared to test for a correlation between these parameters and changes in ocular function in terms of refraction (progressive myopia) or loss of vision (glaucoma and optic neuropathy). Gross changes in the ultrastructures within the tissues of the back of the eye and optic nerve are associated with glaucoma, however the correlation with vision loss is not well understood. Understanding changes in these tissues at the molecular level provided by X-Ray diffraction could improve our understanding of how these collagenous tissues support healthy vision and how any changes could cause vision loss. Characterizing the tissue at this new level could improve our understanding of the structure of the optic nerve and surrounding scleral tissue, as well as identify targets to develop new treatments or interventions, or identify those at risk. These quantitative data will also benefit Finite Element Models that are being developed to understand the biomechanical properties of the back of the eye (Downs et al.).